NFSD: Add nfsd_clid_destroyed tracepoint

[ Upstream commit c41a9b7a ]

Record client-requested termination of client IDs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>